Method and apparatus for sealing cartons



Sept. 17, 1946. v R, GU E I 2, 407,7%i METHOD AND Armnmus FOR SEALING CARTONS Filed Aug. so, 1943 s Sheets-Sheet 1 '7' L591" l H -40 4 Sept. 1-7, 1946. R. GUYER 2,407,781.

( METHOD AND APPARATUS FOR SEALING CARTONS Filed Aug. :50, 1943 I s sheets-sheet 2 Sept. 17, 1946. GUYER METHOD AND.APPARATUS FOR SEALINGHCARTONS Filed Aug. so, 1943 5 Sheets-Sheet s I Rbhlllllk Patented Sept. 17, 1946 METHOD AND APPARATUS FOR SEALING CARTONS Reynolds Guyer, St. Paul, Minn., assignor to Waldorf Paper Products Company, St. Paul. Minn., a corporation of Minnesota Application August 30, 1943, Serial No. 500,497

6 Claims My invention relates to an improvement in method and apparatus for sealing cartons, wherein it is desired to provide a sealed container designed particularly. to hold liquid or semi-liquid material to be frozen.

During the past few years it has become customary to freeze many food products, such as eggs, for. example, and to maintain these products in frozen condition until they are used. Various types of containers have been used for packing such materials to be frozen. Metal cylindrical cans have often been employed for the purpose; Such cans have the advantage of rapid transfer of heat and effective moistureproofness. On the other hand, such cans require considerably more storage space than collapsible rectangular boxes and therefore are not particularly economical to store. Furthermore the cost of such containers is high and the material of which they are formed is at the present time diflicult to obtain.

An object of the present invention lies in the provision of a rectangular box of paper board or similar material which is rendered Water tight through the use of any suitable means and which may be readily set up for use by the user immediately before the product to be frozen is placed therein. As a result these boxes may be conveniently shipped and stored in a minimum of space and may be set up for use at the required time.

A feature of the present invention lies in the provision of a container having a lining of waterproof material therein which extends over the major portion of the inner surface thereof.

This waterproofing material is heat scalable so i that by folding the carton into rectangular shape and applying heat and pressure to certain areas thereof to be sealed, the carton may be rendered virtually waterproof.

terial packed have entered the spaces within flaps and been wasted.

A feature of the present invention lies in the provision of a carton which may be folded and glued in collapsed tubular form while folded flat. Thus the cartons are furnished in flat folded condition and may be folded into hollow tubular formation when used.

My method and apparatus further improves the quality of seal of the ends of the carton. I have found that the ends of my carton when heat sealed are almost completely water tight even when considerable liquid pressure is created on the interior of the carton.

These and other objects and novel features of my invention will be more clearly and fully set forth in the following specification and claims.

In the drawing forming a part of my specification:

Figure 1 is a perspective view of a carton showing the same in closed form.

Figure 2 is a view similar to Figure 1 showing the sealing lid thereof in open position.

Figure 3 is a diagram of the blank from which my carton is formed.

Figure 4 shows the first step in sealing the carton and shows the manner in which the carton is formed in tubular form before shipment to the consumer.

Figure 5 illustrates in perspective the next step in the process of sealing the carton shown in Figure 4.

Figure 6 shows the next step in the formation of the completed carton.

' Figure '7 is a cross-sectional view through 'an end of the carton showing the flap arrangement thereof.

Figure 8 is a perspective view of a type of apparatus which may be used to accomplish my A feature of the present invention lies in the provision of a carton formed with diagonally creased corners arranged so that the side walls and end walls of the container may be folded into rectangular relation and so that a tray is formed capable of holding liquid. The diagonally creased corners when folded form triangular flaps having the contacting fiap surfaces thereof provided with coating of heat scalable material thereupon. By applying heat and pressure to these triangular flaps these surfaces are sealed together so that no moisture can enter the space between the adjacent surfaces of the flap. This feature is of considerable advantage for in the past substantial quantities of the mamethod.

Figure 9 is a perspective view of an end of a slightly modified form of carton construction.

The carton A is formed of a blank illustrated in Figure 3 of the drawings. As best illustrated in this figure the carton includes a bottom wall It) foldably connected along parallel fold lines H and I! to side wall portions l3 and M. The side wall 14- is connected along the fold line 15 to the top panel 16. The side wall 13 is similarly connected along a fold line I! to a top panel IS. The top panel i9 is designed to overlie the top panel is and be adhered thereto.

The bottom wall 10 is likewise connected along a fold line Fit] to an end wall 2| and connected along an opposite fold line 22 to an end wall 23.

A square panel 24 having a diagonal crease 25 therein is foldably connected to the end wall 23 and side wall 4. A similar flap 26 having a diagonal crease 21 therein is connected between the side panel I4 and the end panel 2|. A flap 29 having a diagonal crease 30 therein is connected between the side Wall I3 and the end'wall 23. A flap 3| having a diagonal crease 32 therein is connected between the side Wall l3 and the end Wall 23. These flaps 24, 2G, 29 and 3| are designed to fold along their respective diagonal fold lines 25, 21, 30 and 32 to form triangular flaps or gussets projecting from each corner of the container when the side and end Walls are folded into right angular relation with the base H! of the carton A.

The top panel I9 is provided with end sealing flaps 33 connected to the ends thereof along fold lines 34. These flaps may extend the full width of the end wall panels 2| and 23 or may be formed as illustrated with flaps 35 connected thereto along parallel fold lines 36. The purpose of the flaps 35 will be later described in detail.

The end walls 2| and 23 are provided with projecting flaps or flanges 31 connected to these end walls along double spaced fold lines 39. The purpose of the double fold lines 39 is to permit the flaps 31 to fold down over the triangular flaps or gussets formed by folding the flaps 24, 23, 29 and 3| along their respective diagonal fold lines.

The top panel I6 is provided with a substantially U-shaped out line 40 therein so as to provide a substantially rectangular tongue 4 I therein. Aligned cut lines 42 project inwardly from the open ends of the U-shaped cut line 40, providing a hinge line along which the tongue 4| is foldable.

A substantially U-shaped out line 43 is provided in the top panel l9, this out line 43 defining a substantially rectangular tongue 44 of somewhat larger area than the tongue 4|. The tongues 4| and 44 are arranged to be adhered together in the formation of the carton, the tongue 44 overlying the uncut portion of the inner panel l6. s

In the formation of my carton the blank is preferably folded along two of the fold lines such as, for example, along the fold lines I and I5 or along the fold lines l2 and IT. The panel I5 is 1 arranged to underlie the panel l9 and is adhered thereto. In preferred form the adhesive is usually not applied to the area immediately adjacent the out line 4|] and outwardly therefrom, so that the marginal edges of the tongue 44 are not adhered to the surface of the panel "5 about the out line 40. When the panel |9 has been adhered to the panel I6 the carton is arranged in the tubular form best illustrated in Figure 4 and may be folded flat for shipping or storing purposes, or may be opened into box form as best 11- lustrated in Figure 4.

In assembling the carton for use each carton is preferably folded into tubular formation andthen placed in a suitable form as shown in Figure 4, each carton is then folded into the position shown in Figure 5 of the drawings, the corner flaps 26 and 29 at one end of the carton being folded along their respective diagonal fold lines 21 and 30 so that the end wall 2| is arranged at right angles to the bottom Wall I and so that the flange or panel 3! overlies the flange or panel 33. A heating and pressing element, indicated generally by the numeral 45 in Figure of the drawings is then moved against the end of the carton A, folding the triangular end flaps together as best illustrated in Figure 5 and also sealing the flap 31 upon the flap 33 of the top panel l9.

As best illustrated in Figure 3 of the drawings the inner surface of the carton blank is entirely covered with a water proofing and heat scalable coating 45 withthe exception of an uncoated portion'4| of the top panel IS. The reason why the portion 47 of the top panel I9 is uncoated is to permit the use of regular type gluing machines in adhering the carton in tubular formation. If heat sealing dies or rollers are used in place of adhesive rollers the inner surface of the blank may be entirely coated with a heat scalable material.

The application of heat and pressure against the triangular end flaps tends to seal the contacting surfaces of these end flaps together to make these joints water proof and also to prevent the flow of fluids from within the carton between these contacting surfaces. After one end has been sealed, as illustrated in Figure 5, the position of the carton is inverted so that the other end of the carton may be sealed.

After the triangular end flaps have been sealed and the flaps 33 have been adhered to the flaps 31 the triangular flaps are folded inwardly to overlie the end walls 2| and 23 of the container, as best illustrated in Figure 6 of the drawings.

The end panels flanges 35 are then folded along the spaced fold lines 39 so as to overlie the upper portions of these gussets. The tongues are then inserted between the triangularend flaps and the ends 2| and 23 of the container, thereby holding the triangular flaps folded inwardly and holding the box in proper position. 7

The flaps or flanges 35 when inserted between the triangular flaps and the end walls 2| and 23 of the casing appear as best illustrated in Figure 7 of the drawings. This figure illustrates the end flaps tucked in place so as to lock the triangular flaps in the position shown in Figure 6 of the I drawings. a

In order to quickly and effectively accomplish my method I may use the apparatus illustrated 5 in Figure 8 of the drawings. This apparatus, which is illustrated in general by the letter B, includes a base 49 having a pair of relatively flat parallel uprights 55 mounted vertically thereupon. The uprights 50 are connected by front 50 and rear panels 5| and 52 respectively, which are spaced from the base 43 to provide a longitudinal opening between the uprights 53 adjacent the base. A block or support 53 is secured to the front 5| at the upper extremity thereof and laterally projecting blocks 54 are provided in the upper ends of the parallel sides 50. A plate 55 is formed to extend over the upper end of the rectangular uprights 53, 5| and 52, as well as over the blocks 53 and 54, and this plate 55 extends rearwardly therefrom, being supported by'suitable braces such as 53. In other words the plate 55 forms a flat horizontal table and is provided with an opening 51 therein in alignment with the passage between the uprights 50, 5| and 52. When the carton is folded as illustrated in Figure 4, this opening 57 permits insertion thereof through the table and into the form comprised of the rectangularly arranged supports 55, 5| and 52. A pair of guide tracks orchannels 59 are arranged in parallel relationship on opposite sides of the table 55 to slidably support a pressing plate 65.

This'pressing plate 65 extends into the opposed.

channels 59 and is forwardly and rearwardly slidable therein. A handle 6| on the pressing plate 60 provides a convenient means of moving this plate, and the forward edge 62 of the plate-is preferably rounded upwardly so as to slide over the formed end of the. carton. The central por-- tion 63 of the plate 60 is cut away to provide a rectangular opening as best illustrated in the drawings to save weight and also to straddle the ironing plate supports which will be later described.

Mounted upon the table or plate 55 I provide a pair of upwardly projecting lugs or brackets 64 to which are pivoted the parallel arms 65 attached to the ironing plate 66. The ironing plate 66 is shaped to overlie the triangular flaps forming a part of the carton A, and also to overlie the superimposed fiaps 33 and 31. Aligned pivots 6'! sup port the arms 65 to the lugs 64 and permit the ironing plate 56 to pivot from the upright position illustrated in Figure 8 to a pressing position in which the plate 56 overlies portions of the end of the carton. Obviously the ironing plate could extend over the entire area of the carton end if it is so desired, but it is only required in certain areas of the carton ends and has been illustrated shaped generally to engage these portions of the ends.

A handle 69 is provided on the ironing plate 58 so that the ironing plate may be easily pivoted from one extreme position to the other. A heating element of any suitable type indicated. in

dotted outline at!!! provides a means of heating,

the ironing plate 66 to the required temperature. Line wires ll extend from the heating element through a suitable switch 12 of thermostatic control device to a line plug 13 or any other source of current supply. Any type of heating element may be used and any desired means may be employed to maintain the ironing plate as at the proper temperature. Between the upr ght members t and spaced therefrom I provide a pair of relatively short uprights M which are connected at their upper extremity by a transverse connecting member 15. The members 14 and 55 form a table upon which the carton A may rest when an end of the carton which has been previously sealed is inserted into the form. Obviously the unfolded end of the carton may rest upon the base 49 during the sealing of the first end of the carton.

In operation the carton A is inserted into the form by sliding the same through the opening 51' in the plate 55 and allowing the carton to drop into the form defined by the upright elements 50, 5! and 52. The corner flaps of the end to be sealed such as the corner flaps 2S and 29 are folded along the diagonal crease lines 2'! and 3i] to provide triangular flaps which are folded down upon the surface of the plate or table 55. This action also causes the flange or flap 31 to overlie the flap 33 of the carton. The operator then grasps the handle 69 and pivots the heated ironing plate 55 against the surface of the carton, pressing the triangular flaps and the flaps 33 and 31 together. The heated iron melts the coating material 45 and causes the same to adhere securely. When such heat and pressure have been supplied the ironing plate 65 is pivoted upwardly and the pressing plate 58 remains in pressing position until the adhesive has entirely set, thus firmly sealing the end of the container.

After the container end has been sealed the triangular flaps are folded inwardly to overlie the adjacent end wall 2! of the container and the flaps 3? and 33 are folded inwardly as illustrated in Figure 6, the flap 35 being tucked beneath the triangular end flaps and the end wall 2|. One

sealed in a slightly different manner.

til

end of the box is then entirely sealed. The carton Ais then removed from the form, inverted and reinserted into the form, the end 2! resting upon the connecting member i5 which supports the carton at the proper elevation for sealing the re maining end. The second end of the carton is then sealed in the manner described.

If it is preferred the ends of the carton may be If it is desired the fold lines 36 may be omitted and the end flaps 35 extended the entire width ofthe flaps 33, thus providing an unfolded end panel 16 the full size of the panel 21. This panel 16 may be folded over the end 2! and sealed in this position by sealing tape such as 11 illustrated in Figure 9 of the drawings. The triangular flaps are thus sealed in place by means of the sealing tape H.

In accordance with the patent statutes, I have described the principles of construction and operation of my method and apparatus for sealing cartons, and while I have endeavored to set forth the best embodiments thereof, I desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

' I claim? I l. A container comprising four panels foldably connected together toform a top panel, a bottom panel and side wall panels; a fifth panel foldably secured to one of said side Wall panels and adapted to overlap said top panel and be adhered thereto, end panels foldably secured to said bottom panel, connecting flaps secured between said end panels and said side wall panels, a heat-scalable coating on the inner surface of said container panels, said connecting flaps being diagonally folded and adhered together by said coating, and flanges foldably connected to the ends of said fifth panel, and to the upper edges of said end panels sealed together by said coating.

2. A container comprising five panels foldably connected together along substantially parallel fold lines, the end panels of said five panels overlapping and adhered together, closure panels foldably connected to opposite ends of an intermediate panel of said five panels, connecting flaps foldably connected to opposite sides of said closure panels and to the panels next adjacent said intermediate panel, said connecting flaps being folded along diagonal creases, flanges on said closure panels and on opposite ends of one of said end panels, a heat scalable coating on said connecting flaps and said flanges on said closure panels adhering said flanges together and adhering said connecting flaps in folded relation.

3. A container comprising a series of five panels foldably connected together along substantially parallel lines, the end panels of the series overlapping and being adhered together, closure panels foldably connected to opposite ends of an intermediate panel of said series, connecting flaps foldably connected to said closure panels along opposite edges thereof, flanges foldably connected to said closure panels along lines parallel to the foldable connections between said intermediate panel and said closure panels, flanges foldably connected to the ends of. one of the end panels of said series, and a heat sealable coating extending over the inner surface of said container, said coating extending over said connecting flaps and at least one of said flanges, said connecting flaps being folded along a diagonal fold line and adhered in folded relation by said coating, and said flanges being adhered together by said coating.

4. A container comprising a series of five panels 'foldably connected together along substantlally parallel fold lines, the end panels thereof overlapping, adhesive between said end panels adhering the same together, closure panels foldably connected to the opposite ends of an intermediate panel of said series of panels, connecting flaps foldably connected to said closure panels and to the panels of said series adjacent said intermediate panel, a heat scalable coating on the inner surface of each of said panels with the exception of the end panel adhered overlying the other end panel of said series, end flanges on said overlying end panel, and flanges on said closure panels, said flanges being sealed together by said coating, said connecting flap being folded along a diagonal fold line, and heat-sealed in folded relation by said coating.

5. A container blank comprising a series of five panels foldably connected together along substantially parallel fold lines, one end panel of said series being slightly narrower than the other end panel, a closure panel foldably secured to each side of the central panel of said series, connecting flaps foldably connected to said closure panel and to the panels adjacent the central panel of said series, diagonal fold lines in said connecting flaps terminating at the juncture between said central panel, said closure panels, and said adjacent panels, a flange foldably connected to each said closure panel along a line parallel to the fold lines connecting said closure panels to said central panel, flanges on said other end panel, and a coating of heat-scalable material extending over one surface of said narrower end panel, said central and adjacent panels, said closure panels and flanges secured thereto, said connecting flaps, and that portion of said other end panel not designed to overlap said narrower end panel.

6. A container comprising a series of four panels connected together along substantially parallel fold lines, means connecting the end panels of the series together to hold the panels in tubular relation, end panels foldably connected to an intermediate panel of said series, con necting flaps secured between said end panels and the panels next adjacent said intermediate panel, a heat-scalable coating on the inner surface of said container panels, said connecting flaps being diagonally folded and adhered to- ,gether by said coating, flanges foldably connected to the ends of the panel opposite said intermediate panel, and flanges secured to the upper edges of said end panels, the corresponding flanges of the end panels and of the panel opposite said intermediate panel overlapping in face contacting relation and sealed together by said coating.

REYNOLDS GUYER. 

